I'm doubling mine today for the huge price tag of about 500 EUR. Bringing me up to 4 kWp, which is well over 100% of my net use.

Indeed. My point wasn't that wind is better than solar. But having both is nice. Solar isn't available 100% of the time, and if the periods of low solar are longer than battery capacity, then you wind up back on the grid.

Diversifying your power sources means that even if it's cloudy, you still have wind. Is it a good idea financially? No. Is it a good idea if you are committed to the idea of maximizing time off the grid, yeah. Cost per kWh isn't the only factor in why someone might want home power.